Fuel economizer



2 Sheets-Sheet l v w. G. ciRlFFlN FUEL EGONOMIZER med Dec, 21. 1921 AMay2z, 1923;

INVENTOR.

kToRzx/EY.

May. 22, 1923. A I 1,456,057

` v' W.. G. GRIFFIN FUEL ouomlzzx v Filed nec. 21. 1921 f l 2sheets-s119632 By n Y QA d@RA/EY.

./W //INVEN TOR.

Patented May 22, i923,

aufn srars i lg? r' site,

FUEL ECONOMIZER.

Application filed December 21, 1921.

To all whom t may concern.'

Be it known that I, VILLIAM Gr. GRIFFIN, a citizen of the United Statesof America, residing at Washington, in the District of Columbia, haveinvented certain new and useful Improvements in Fuel Economizers, ofwhich the following is a specification.

The present invention relates broadly to new and useful improvements infuel economizers, and has particular reference to those devices of thetype that are adapted especially for application to the smoke stack orother exhaust conduit from Vthe furnace and are designed to convert theunburnt products of combustion passing through the exhaust conduit intoa combustible fuel and returning the same to the fire-box of the furnacewhere it is ignited and consumed. I

lWhile it has heretofore been proposed, and in some instances carriedinto practice, to make available for combustion 1n the lire-box of thefurnace those unburnt prodto introduce to the fire-box the mixed air andunburnt products of combustion in sufiicient quantities to achieve theconsumption. of the escaping products to the extent that is possible bythe present invention.

It is therefore the object of this invention to make possible theutilization of the heat-producing properties of coal and other fuel bymeans of a method and construction, whereby l'iighly heated air isbrought into contact with the hot gases at a point after they leave thecombustion chamber. and in a manner to form a readily combustiblemixture that will be drawn down into the furnace and burned. `While I amaware that it is not new to introduce air into these uprising gases, theintroduced air heretofore used has been of thetemperature of theatmosphere and cools the gases and thus Serial No. 523,907.

defeats the intended purpose, which must be accomplished very quickly.

It is also an object of this invention to chamber by the return drafttherein caused by the rarefaction of the gases in the combustionchamber.

A further object of the invention is to e'ect a greater admixture of airwith 'the gases than otherwise would be possible, by causing the draftof the uprising gases from the furnace to divide and each divided draftto pass through an expanding and air-mixing chamber in order thatincreasing facilities may be provided for greater air introduction andmore thorough mixing thereof with the products of combustion and theproduction of maximum results.

Another object of the invention is to relate the air inductor and thegaseous inductor to each other in such manner that the amount of airdrawn into the drum will be determined by the density of the productsescaping from the furnace, and will therefore at all times and under allconditions be that amount which will most efficiently support thecombustion of these products which are returned to the fire-box of thefurnace.

One feature of the invention resides in the method of improvedcombustion which consists in introducing highly heated air into theuprising unburnt products of combustion and causing the mixture of airand unburnt products of combustion to be introduced into the furnace,preferably through a return draft traveling through the uprising gases,whereby the same are drawn back for combustion with the requisite oxygento support the same.

The apparatus for practicing the above method consists broadly in acasing or chamber to yform an intermediate portion of the exhaustconduit ofa furnace having one or more 'enlargedsection's lto ex-pandthegases and smoke passing therethrough and 5 provided with air passagesleading into the economizer which includesy asthe .essential centralportion.v ofy the .-casingf and means:

for heating Athe air before it is ldrawn into the casing.

.The invention further consists 1n a fuel elements of construction abody casing to form anV expansion Ichamberadapted to `be interposed intheexhaust conduitfoflthe furnace,l a plurality of air openings throughwhich' fresh air vmay enter the casing, a mirn drawing off `from theproductsescapingfromy the furnace through the conduitthose oxy-l"carbongases and kpure carbon particles `which ing chamber which issegregated from` thev "interior'of the casing, a' means for.` directingthe-'air enteringl the opening'm the mixing' chamber, andla means for"coincidentally will, when combined with air, produce a mixture of frelatively -liigh combustibility y and-of relatively highcombustiontempera-g ture, so that the `amo-unt of 'heat vrescuedIfromwhat otherwise' would be waste prodg ucts, Iwill be of maximumextent.

-The inventionialso'consists in other novell 30 features ofarrangementand-construction ofl parts allras hereinafter described, andas specifically pointed l' out yfin the a appended' claims.vr l

Aln the .accompanying drawings yfa lpreferrediform ofndu'alconstruction, in

which view `oneof thev duplicate air and gas inductorsv -is-shown infull line yFigure 2 atop orv plan view ofthe device;

Figure 3 a ybottom view thereof; and V Figure 4L a detail showing a topview vof one ofzthefhoops constituting a part 'of the gaisinductingmeans andshowiig the supportingl i 45 spider therefor.

Referringto thejdrawingsfor aidetailed descriptionth'ereof, 10:indicates a casing preferably"constructedof sheet metal and de-isignedto be Finterposed in thesmoke rpipe or exhaustconduitof-afurnacm'and to fornr Va chamber. thatfzconstitutes'apartof the draftvpassageway and into which the uprising products of combustionexitingthrough the conduit must enter -andybe enpandechandy for thelpurpose: ofwconlnectmg ltr-up inthe con; f

duit,\ it: i is formed Y' withl y centrah flanged vfiopeningf11lat thefurnace fendftowreceive and makea unionwviththe sectionifof pipe 12leading directly lfromthe furnace, or if de sired; .the union can be'madedirect-ly with thelflanged pipe provided on' furnaces forthe `Figure1 isf-alongitudinal sectional view r of the fuel economrzer, showing thesame inr which completes the same to a chimney or stack. ln thevpreferred form shown, in which a double form ofthedeviceispresent, adouble elbow 14E forms the means ofdividing thedraft passage and permitsthe ap plication. ofthe-invention separately to each draft to furtheramplify the economic resultsinyapplying the principles of the invention,which are present and complete in each part and may be practicedwith butone of the. duplica-te parts connected up 'Vsingy in the exhaustconduit. Forthe purpose `of the dual' form shown, the'double elbowl-nnites i the 'divided draftjpassing through the sections 16 and 17-which fornr the connections between the double elbow, and permits theVunited draft to continuethrou'glrthe :remain-v ing portion of theexhaust conduit.

tThe sections 16 andv 17y each includes? an expansion chamber l1 8 oflarger crosssection than the exhaust conduit,- and which-` at its'endsis commensurate witheach opening 19 of thedouble elbow 14:` and'`forms atene end a juncture with the :saidl ielbow'This e);-` pansionchamber 18 is outwardlyliared to an intermediate point.thereofrand''then` contractedto receive a short'waist section-20,

the chamber 21, having a: co'nical'top 22n and 4- base portion`22b ofinverted frusto-conical form and in. open-relation at its flower endwith the chamber 21. "From the baseportion of the chamber 22 air ducts423 extend into open relation with the airon the exterior of preferablyof the cross sectional size of the 1 the chamber 21,'the'1pipingforming'ithese ducts extendingthroughl the/sides y2 l and being hangeddown on theexterior'thereof,

so that the 'air entering the openings will beV solely directed into theinterior'chamber 22. ln order that' they air entering theuchamber 22 maybe heated `to a temperature 'that `will permit it to readily mix: withthegases and unburnt products of'combustion,` there :is

rounds the'sections 16 and 171as made up of the partsyconstitutingit;which drum is pro-L vided with openings 242% at :thebottom there- 'of :to permit the entrancepf air, which as` indicated bythe arrows,4 isfheatedf it risesf-feXhausticonduit; vOnltheopposit'efory topto-th'e upper part ofi-the interior ofthe end thelcasing-is provided withI a flanged 'enit` opening 13 to: makeaunionwvith f that portion beingfof suchY aI degree 'of temperature. asyto 65 of ftlieconduit or -smoke pipe (notf shown A)"Hreadilyr mix withthe products ofcombustioni drum `where it. is drawn intoV the chamber 22I As a further kmeans of inducing heated air into the chamber 22, atube25 is centrally disposed longitudinally through the casing or section(16 and 17) and through the elbow 1a, the same extending through andbein@ supported at its lower end on a cap 26 closing a side opening 2Tto permit ready removal of the tube with its associated parts forcleaning'7 the tube being secured to the cap 26 by nutsVV 28 land 29,andy being removably centered in a spider 30 secured within the airchamber 22 so that with the removal of the cap 26 the tube will bewithdrawn from the central opening of the spider support.

At this point it should be explainedtliat the products of combustion.entering the exhaust conduit in their outward passage travel along thewalls' of the conduit, there being a. tendency to hugv the Wall, leavingalong the axial path of the' conduit a rei turn current. This conditionis due` mainly to the rarefactio-n of the air and gases within thefurnace, which rarefaction is making a I from the hub portion andsecured at theii` ,lemand always for more air, and this air which `seeksentrance alo-ng an axial path within the conduit forms a part of thereturning current." In the' present invention this condition is takeninto consideration and is 'augmented by the expansion given the gases inthe present device, the effect of the expansion starting in theelbow'section 1e and further taking place in expansion'chambers 18 acts,not only as a retardent to the outgoing'current by rarecation,butrincreases the return current so that the air introduced into andalong the axial path by the air inductor assists materially in buildingup this return current especially in that the air is heated sothat'itwill unite with the outgoing gases and much'of `the unburntproducts of combustion returned and consumed.

As a means to give a nozzle eifect within the device of the induced airand at the same tiiue induce the gases along a considerable path thereinto mix with the heated air'and become part of this return current, therehas been provided a nozzle structurel that is built up of a multiplicityof frusto-conical.

hoops 31 horizontally supported upon the heated air tube 25 with theflare thereof upward, so that each hoop will extend well within theiiext adjacent lower hoop and leave the sides of adjacent hoops spacedapart tofoi'm the `-eas-inducing openings 82 through which theunburnt'products of coinbustion are drawn, these hoops being also spacedapart from the tube 25 to form a lnozzle passage or mixing chamber 33surrounding' the said. tube for the heated air from chamber 22 and theindrawn gases through the opening 32 to thoroughly commingle and becarried along the axial path of the device and exhaust conduit into thecombustion chamber of the furnace. 'it will be vnoticed that the mixingchamber or nozzle formed by the series of flanged hoops 31 is arrangedto receive the heated air from the air inductor chamber 22, thedischarge opening of that chamber being within the initial or top hoop,and tha-tfthis mixing chamber or nozzle-extends axially Withtheexpansion casing and Well Within the ex-y pansion chamber V18, so thatthe current of the products of combustion which will be more or lessretarded at this point of great-A est expansion as Well as raretied,assists in causing the unburnt or more volatile products to seek thereturn current through vthe gas inductor openings, the surface of thelia-red walls of the. gas inductorhoops tending also to arrest theoutward current and deflect it downward'and inward.

As a means of supporting the flared hoops 31 of the inductor nozzle, aspider 34 is 'v employed which consists of a hub portion 34j* to receivethe tube 25 and clamp 'thetube therein, and arms or spokes extendingends to the hoop, the hub and arms being formed preferably as shown inFigure 4 in which four strips of sheet metal are so bent and united asto form a simple and inexpensive Spider construction for the purpose.

From the foregoing it will be seen thatv the present device has notymerely proceeded on the principle that atmospheric'air may be let intoVthe exhaust conduit at a point where the same is expanded to promotefuel consumption in some part, but that the in! vention has sought n avery substantial vway to extend this principle so that a veryconsiderable quantity of air Will not o-nlyfbe properly combined withthe escaping products of combustion but delivered with theA troducedatmospheric air does not take place quickly enough to effect thoroughcommingling of air and gas to secure the-benetit present whenheated'air'is introduced andv is objectionable in that it lowers theignition point of the gases. Further the presence of the axial `returncurrent is 'made This result has proceeded, as

use of when cold 'air is introduced only slightly. if at all, and mustbe au'ip'litied as it .is in the present invention by thebo-osting`cui-rent of heated air and the counteracting of the outward boundcurrent which is retarded by the general expansion of the gases andwhichare given a further expan sion and retardation in the expansionchainber 18q where the conditions are present for the induction of theunburnt productsintothe fproducts fof,.,cornbustion, means con-L tainedWithin the f :chamber for V supplying freshair in .combustionfsupportingquanti. tiesto `,tha-products of vcombustion exiting.` ,15: through @theconduit, 1 said Vrmeans being further adapted ,to initiate la returncurreht'of, such mixture Ythrough *.the conduit totheifurnacealonga pathaxially yrelated to the conduit.

;` 2*.The.combinationwvith the exhaust con-l duitrof a furnacey ofuanyexpansion ychain ber forminga -partthereof forgthe passage ofi ytheproducts of,- combustion, ,means contained Withinf'the 'chamber for.supplying fresh,4 air ,in combustionfsupporting quantities to thelproductsofscombustion exiting through "the conduit, saidmmeans being ifurther adaptedrto strengthen aretufrn cur-A rent present` along -afpathaxially krelated 30.1fto, 'the conduitxfdue! to rarefaction Aof airWithin the combustion chamber and induce the mixing `with, thel air iand` return to.,y the furnace7 of y a.; substantial `portion of ,theproducts of combustion exiting through the ficonduit.y l

The f combination With the exhaust con- 'duit of a' furnace, of an.expansion chamber A forming avpartthereof fonfthe productsofcombustion, means contained `Withinrthe 40# chamber forsupplying'freshair in combustionfsuppo'rtingj quantities L and means 'i for heatingtheair before :it isfintroduced into saidair,supplyingmeans.

- 4.' The combination With .the exhaust con-' 4'5 -\duit of ,av furnace,ofan expansion cha1nber forming a part thereoff for thepassage of'the`products of'combustion, means Withinuthefexpansionchamber fordirectinga Y current-ofy air-therein in a direction oppo- 5Qsitei to thenormal exiting draft Ithereof,

and means exterior to said conduit forv heating'fthe air introducedtherein.

5l" The combination with the exhaust con-r duit. of af' furnace, of an;expansion chamh-bery forming apart ythereof lfor they pas-vsageoflthe,products of combustion, means Withinlthe expansion rchamberfor heating'. and-,directing'aicurrent of air-therein lin ak directionopposite `to the normal exitingv draftizthereoL-andumeans exterior tosaidv v conduit for `preheating the air before ity is admitted toi-theheater-` ,withinthe conduit. 6;:The combination Withthe exhaust con-kduit; of au furnace, of any expansion chamerabertformingfapartthereoffor the lpassage the pro-ducts' of'.l combustion,.- andanlair in` vber for theproducts ofC0Irlloustion,y an air the ,conduit-fromthe normal. path andfto of Vthe products of y.combustion,A ajchamber.Within the expansion chamber for heating and ,discharging air therein,means for:

r'furnishing,preheatedair to said heating chamber disposedvvithin ytheconduit, and 7.0A furtherfmeans for furnishing preheated air tetheIheating chamber.l from a source exterior tothe conduit. w

7.v The .method of imprpving the ICQ-mtas; n

tion offuels, which consistsin yexpanding 75 ucts of combustion .toenter the `furnace throughl the. said conduit and be consumed.

8;; Thezmethodfof improving the combusf tion of fuels, WhichconsistsinexpandingA 85` the productsfof combustionv Whileexiting n through theexhaust, conduit ofwa furnace, introducingv into; the said yexp anded-fproduct heated. air, that/has received .its heat ybefore itisconducted within said conduit, further heating. said air Within.k theconduit by the heat from the products of ycombustion and before itscommingling therewith, and causf ingthe mixturenof heated air andproducts` ofcombustion .to enter-the.furnace-*through the'said conduitandlxbe consumed; i i

9. .The 5 combination `with. the exhaust .conduit `of a--fui`nace,\ofanexpansionchamber forming ag part "thereof for the passage of 10o duotordisposedthereon extendingina di,-

`rection opposite to Vthe anormal vdraft of the conduitgaand having a`discharge opening'at its linnernfend,. :said inductor. having slde popenings for'theinduction `into the inductor. of the surroundingproducts of combustion.

'10. TheV combination with ofthe.,V exhaust conduit-of a furnace, of anexpansionvchaminductor open `tofthe atmosphere for supplying a currentof fresh air to .the `chamber, and a'coaoting inductor disposedQto ef- Ai feet adeflectionof a substantial portion of theprod'uctsof,combustion.passingthrough i' conveythem tothe pathofthe air 'currentimmediately adjacent to-the exit'of the air;

inductor. i, 'f

11: The l combination .With the ,A exhaust l conduit of a furnace, of anexpansion fcham-l ber;y for the products of' combustion, vkan air.inductor communicating ivithfthe atmos, phere for .supplying acurrentof .fresh air, to the chambera gas inductor coacting with the Y air'inductor and disposed to effect the 4. deflection of a portionof thegaseous products passingqthrough the A,con duitfrom theirv normal pathtothe path of, air icurrent exit-fing .from theairinductor. ,K j

12. The `colnb,inationj with4 the vexhaust retener conduit of a furnace,of an expansion chamber for the products of combustion, an inductorcommunicating with the atmosphere for supplying a current of fresh airto the chamber, a gas inductor coacting With the air inductor anddisposed to effect the deflection of a portion of the gaseous productspassing through the conduit from their normal path to the path of aircurrent exit-- ing from the air inductor, the deflection of gaseousproducts from their normal path, their conveyance to the path of the aircurrent attained by means of an induced current set up in the gasinductor in response to the exit of the air current from the airinductor into the gas inductor.

13. The combination With the exhaust conduit of a furnace, of anexpansion chamber for the products of combustion, an inductorcommunicating With the atmosphere for supplying` a current of fresh airto the chamber, a gas inductor coacting with the air inductor anddisposed to effect the deflection of a portion of the gaseous productspassing through the conduit from their normal path to the path of aircurrent exiting from the air inductor, and a mixing chamber located atthe point when the said deflected products of combustion enter the pathof the air current.

14. rlhe combination with the exhaust conduit of a furnace, of anexpansion chamber for the products of combustion, an air inductorcommunicating` With the atmosphere, and a coacting gas inductor,concentrically disposed with respect to the air inductor.

15. The combination With the exhaust conduit of a furnace, of anexpansion cham-A ber for the products of combustion, an air inductorcommunicating with the atmosphere, and a coacting gas inductor,concentrically disposed With respect to the air inductor and partiallyenveloping the air inductor.

16. The combination with the exhaust conduit of a furnace, of anexpansion chamber for the products of combustion, an air inductorcommunicating with the atmosphere, and a coacting gas injectorconcentrically disposed with respect to the air inductor and surrundingthe inner end of the air inductor.

17. rlhe combination with the exhaust conduit of a furnace, of anexpansion chamber for the products of combustion, an air inductorcommunicating with the atmosphere, and a coacting gas injectorconcentrically disposed With respect to the air inductor and surroundingthe exit mouth of the air inductor. f

18. The combination with the exhaust conduit of a furnace, of anexpansion chamber for the products of combustion, an air inductoraxially disposed therein, anda gas inductor concentrically disposedv1with re-y spect to the air inductor and surrounding the inner endthereof.

19. The combination with the exhaust con` duit of a furnace, of anexpansionvchamber for the products oficombustioman air inductor axiallyyIdisposed within the chamber, a series of annular exhaust passages forconducting products of combustion from the chamber, and a gas inductor.

20. The combination with the exhaust conduit of a furnace, of anexpansion chamber for the products of combustion, an air inductor,axially disposed Within the chamber, and means for forming a series ofexhaust passages for conducting products of combustion from the chamber,said series of passages, being concentrically disposed With respecttothe inductor.

2l. The combination with the exhaust conduit of a furnace, of anexpansion chamber forming a part thereof for the expansion of theproducts of combustion, means for inducting heated air into the chamberalong an axial path therein, and means for indue ing the products ofcombustion to be drawn into the induced a-ir along said axial path,whereby the mixture is returned to the furnace through the conduit forconsumption.

22. The combination With the exhaust conduit of a furnace, of anexpansion chamber forming a part thereof for the expansion of theproducts. of combustion, means for inducting air into the chamber alongan axial path therein, and a gas inducing nozzle coacting with the airinducting means, said nozzle having openings along its length forinducing the products of combustion therein and directing the mixtureintothe furnace through the conduit.

23. The combination with the'exhaust conduit of a furnace, of anexpansion chamber forming a part thereof, means Within the chamber forinducing air therein, means for directing the induced air along an axialpath therein, said means comprising a series of flared hoops arranged toextend in spaced relation one With the other to deflect the outgoingproducts of combustion Within the hoops to mix With the induced air anddirect the mixture to the lire-box of the furnace along the return pathof the conduit'.

24. The combination with the exhaust conduit of a furnace, of anexpansion chamber comprising a portion in Which the maximum expansion ofthe products of combustion is present, means for inducing a current ofair to said maximum expansion portionin opposite directions to theexiting' current and along the axial path of the chamber, and means forinducing 'the expanded and retarded products to be drawn into the axialcurrent and mixed with the air and returned by said current to thefurnace.

25. Thel combination With the exhaust con-

